Decided to get dreads.

I'm still pretty young and my hair is currently too short to dread but it grows pretty fast so I'm doing my homework on it now to get ahead. If I do dreads I want to know EXACTLY what I'm getting into. I've heard a lot of mixed opinions on it but I think I want to use Dreadhead wax. I saw some pretty good reviews on it and not much argument against it. Thoughts? I also decided on the backcombing method. Is this a good method for beginners? Also, I'm Caucasian, with slightly thin hair and it's slightly oily. Will this affect my dreading? Suggested length for dreading? I don't want them to stick out or look bad just because it's too short. I'm still in highschool so that would probably be bad. Suggestions? I'd appreciate any help or guidance.
updated by @adrian-keenan: 01/13/15 09:09:08PM

But won't twist and rip hurt? And I want thin dreads that look nice; I don't want them to frizz too much or be thick and knot together. I want dreads that look decent, thin, and clean. Not all stuck together like large three inch dread lumps.

But won't twist and rip hurt? And I want thin dreads that look nice; I don't want them to frizz too much or be thick and knot together. I want dreads that look decent, thin, and clean. Not all stuck together like large three inch dread lumps.

How long should my hair be for that method? And how do I do "twist and rip"? I read the article but I don't understand what I'm supposed to do. Can I still wash my hair? Should I not use conditioner? Do I need a specific shampoo? Can I still wash my hair every day? Or at least every other day? How can I make my dreads thin and at least mostly even?